Power-transmission mechanism



l Jam @9' @EL H. H. BRQWN 39779565 POWER TRANSMISSION MECHANISM Filed Feb. 5. 1929 4 sheets-sheet 1 /9\` 9 I a 7@ gl a l TULA-vai' S- Hj 99,/ .16/

im 6, B933., H. H. BRQWN POWER TRANSMISSION MECHNISM 4 Sheets-Sheet 2 gru/muto@ Filed Feb. 5. 1929 Harry /2 5m wn Um @y w31 d v H. H. BRQWN lg' POWER TRANSMISS ION MECHANI SIv Filed Feb. 5L 1929 4 Shee'S-Shee '5 attac/Manga Em @y 319331, H. H. BROWN @@7555 POWER TRANSMISSION MECHANISM Filed Feb. 5. 1929 4 Sheets-Sheet 4 Patented Jan. 6, 1931 muren sr HARRY H. BROWN, F LOB ANGELES, @A LE'BNIA POWER-TRANSMISSION MECHANSM Application filed February 5, 1929. Serial Ko. 337,578.

This invention relates to power transmission mechanisms and, more especially, to that type of power transmission mechanism in which the power is transmitted, at least in part, hydraulically.

This 'application is in part a continuation of my former application, Serial Number 334,440, filed January 23, 1929.

An object of the invention, in general, is

to transmit power economically from the prime mover to the mechanism that is to be operated.

More particularly, an object of the invention is to elfect change of speed of the mechanism that is to be driven through the transmis-sion mechanism in accordance with the power requirements of the driven mechanism.

Another object is to eiect the change in speed automatically in accordance with the 0 power requirements.

Another object is to provide a series of pump units and valves to control the discharge of said units so that-said discharge can be directed to the propelling unit or units or by-passed.

Another object is to provide a number of pumping units and valvestherefor to control the exhaust therefrom, as mentioned above, together with the provision of governor-operated means for controlling the valves in accordance with the speed of the mechanism being driven.

Another object is simplicity of construction and operation.

Further objects and advantages will appear in the subjoined detailed description.

The accompanying drawings illustrate the invention.

Figure l is a plan view of a power trans- 0 mission mechanism constructed in accordance with the provisions of this invention, a prime mover, a driven-axle housing, and wheels mounted thereon, also being shown.

Figure 2 is a plan view of the pumping unit and engine fly wheel, the housing of the pumping unit, together with portions of the internal mechanism, being shown in section.

Figure 3 is a vertical section of the pumping unit on the irregular line indicated by 3 3,.Figure 4:.

Figure 4 is a vertical section on the line indicated by 4 4, Figure 3.

Figure 5 is a sectional view similar to Figure 4 showing the exhaust valve and its controllmg mechanism in diderent positions than in Figure 4.

Figure 6 is an enlarged view of the rocker arm and cam shown in Figure 5, some of the parts being in section on the line 6 6, Figure 2. 6 0 Figure 7 is a view similar to Figure 6 showmg another one of the rocker arms and its operating cam, some of the parts being in section on the line indicated by 7 7, Figure 2.

Figure 8 is an enlarged detail, partly in 65 section, 'of one of the valve operating rocker arms and its operating rod. Figure 9 is an enlarged vertical view, partly 1n section, on the line indicated by 9 9, Figure 1.

Figure 10 is a view, mainly in section, on the rregular line indicated by 10 10, Figure Figure 11 is an enlarged horizontal section of the propelling unit.

-Figure 12 is a vertical section on the irregular line indicated by 12-12, Figure 11.

Figure 13 is a fragmental sectional view on the line indicated by `13 13, Figure 12.v

Figure '14 is a view similar to Figure 13, 80 showing the valve in a dierent position.

Referring to the drawings:

rihe power transmission mechanism `comprises, a pumping unit A, and an impelling unit B, the pumping unit A being coupled 8 5 to a prime mover C, and the impelling unit being coupled, in this instance, to driving wheels indicated at D.

The construction and arrangement illustrated in Figure 1 is that employed in mo- 99 tor cars, but it is to be understood that the invention may be used wherever it is desired to obtain various speed'ratios between the prime mover and the mechanism to which the power is transmitted, but for illustrative purposes, the prime mover is shown as1 an internal combustion engine and the wheels D and their mounting constitute portions of a motor car.

rFhe pumping unit A and impelling unit In B areL connected to each other by pipes 16, 17 so as to rovide for circulation of the hydraulic medium, the pipe 16, in this instance, constituting the pressure feed and the pipe 17 constituting the return line. The return line 17 is provided with a manually controlled valve 18 of any suitable construction so as to check the return flow of the hydraulic medium through the line 17, and thus produce a braking action upon the impelling unit.

Now describing more particularly the pumping unit A, illustrated to advantage in Figures 2 to 8 inclusive, the pumping unit comprises a series of rotors 19 fixed to a shaft 20 by keys 21, or their equivalents. The

rotors 19 turn within a casing 22 which has an inside diameter somewhat greater than the rotors 19. The shaft 2O is mounted at its'opposite ends in bearings 95 supported by the end walls 96 of the casing 22. The bearings 95 are positioned eccentrically of the axis of the casing 22 so that each rotor 19 at one side will Contact with the wall of the casing 22 and at other points in its periphery will be spaced from said casing. The inner face of the casing is circular and said casing is cellular, with a rotor turning in each cell or compartment 23, partitions 24 separating adjacent compartments from one another. Each of the rotors 19 is provided with radial slots 25 in which are mounted vaiies 26, each 'of which is urged outwardly into engagement with the casing 22 by a coil spring 27.

At points where the rotors 19 are spaced from the inner face of the casing 22, said casing is provided with a number of inlet ports 28 which open from the interior of the reservoir 29 to the various compartments 23. In this instance, the casing 22 is mounted within the reservoir 29 and said reservoir is made of suicient capacity to hold the necessary amount of oil for transmitting the power from the pumping unit to the propelling unit.

Assuming that the rotor 19 turns clockwise in Figure 4, the casing 22 is provided forwardly of the ports 28 with a pair of eX- haust ports 30, 31 for each compartment 23, and each of these pairs of ports opens into a valve chamber 32 in the casing 22. The inner face of the casing 22 is provided with a circumferentially extending by-pass channel 321, one for each compartment. The channels 321 extend clockwise from the lower sides of the ports 31 to points slightly removed from the points of contact of the rotors 19 with the inner face of the casing 22. These by-pass' channels 321 prevent back pressure against the vanes 26.

Slidably mounted in each of the valve` chambers 32 is a sliding valve 33 provided with a port 34 that may be broughtinto registration with the port 30, or out of registration with said port, according as said valve 33 is in its lower or upper position.

Each of the valve chambers 32 is provided in alignment with the port 30 with a by-pass port 35 that opens into the reservoir 29, so that when the valve is in the position shown in Figure 4, the oil is simply circulated through the pump compartment and the reservoir. a

At its lower end, each of the valve chambers 32 communicates with an outlet 36 to which the pressure line 16 connects. Thus, when a valve 33 is in its raised position, the oil passes from the port 31 into the valve chamber and thence into the pressure line 16.

The means for operating the valves 33 are constructed as follows: i

Each of the valves 33 is provided with a valve stem 37 which is opera-ted by a rocker arm 38. All of the rocker arms are fulcrumed by a pin 39 which extends longitudinally of the casing v22 and is supported at its opposite ends in lugs 40 that project upwardly from the casing 22. 4The arms 38 are provided with openings 41 through which the valve stems 37 pass, and surrounding each of the valve stems are coil springs 42, 43 which are positioned above and beneath the rocker arms, the's rings 42, 43 being conined on the stems y nuts 44, 45. The purpose of the springs 42, 43 is to store power so as to quickly throw the valves 33 from one position to another, a spring pressed ball detent. 46 being provided in the casing 22 for .each of the valves 33 for yieldingly holding the saine in either its upper or lower position, each detent 46 snapping into either one of seats 47, 48 in the valve stem associated with said detent. When the detents 46 engage the seats 47 the valves 33 are positioned to by-pass the oil, and when the detents engage the seats 48 the valves are in position to admit the oil to the pressure line 16. It Will be readily understood that movement of any one of the rocker arms 38 upwardly will first act to compress the upper spring 42 until the pressure is suticient to release the associated valve 33 from its detent 46, whereupon expansion of the spring 42 will act to quickly throw the valve into its upper position. Downward swinging of each rocker arm 38 will store power in the associated spring 43 so as to quickly throw the valve into its lower position.

A means is provided to operate all but one of the rocker arms 38 in accordance with the. speed of the propelling unit and, in this instance, said means includes a governor which is indicated in general by the character 49 which may be of any suitable type and which, in the instance illustrated, is of a well-known ball type. In this instance, the forwardinost rocker arm 38 is manually operated by an operating rod 50 which passes through a stuiiing box 51 in the wall of the reservoir 29. One end of the rod 50 is pivoted at 52 to said forwardmost rocker arm 38, and the posite ends oth "r end of the rod extends to Within reac ofthe operator. The remainin rocker arms 38 are operated by cams 53 xed to a 'rock shaft 54 that projects from the reservoir 29 into a housing 55 that is secured to the rear end wall of the reservoir. 53 is provided with a cam groove 56 into which projects a follower 57 mounted on the associated rocker arm 38. rThe cam grooves 56 are constructed and the cams so timed that turning of the rock shaft 54 in one direction will successively raise the valves 33 beginning with the second one from the forward end, and turning the said rock shaft in the opposite direction will successively depress said valves beginning with the rearwardmost valve. To accomplish this each cam groove 56 is provided with a high point 58, and the high points of the dierent cams are angularly spaced so as to successively come into action against the associated followers 57.

Within the housing and fixed to the rock shaft 54 is a spur pinion 59 in mesh' with a rack 60 mounted on a shaft 61 of the governor 49. The governor shaft 61 is driven by mitre gears 62, 63 from a shaft 64 which, in turn, is driven by the propelling unit B.

Referring more partlcularly to the construction shown in Figures 11-14 inclusive, the propelling unit B is constructed as follows: l

In this particular instance, the propelling unit B functions as a differential drive and, accordingly, its propelling rotors 65 are mounted in separate chambers 66 in a housing 67, said housing being secured by bolts 68, 69 to axle housings 70 which enclose the halves 7l of the axle. ln this particular instance, the axle drives the wheels D, in a manner well understood in the art relating to motor cars. One of the axle sections 71 drives the shaft 64 through mitre gears 72, 7 3 which are housed within the associated housing 70. Since, in this instance, the opof the shaft 64 are out of alignment, said shaft 64 is of sectional construction and the sections are connected by any suitable form of universal joints 74.

The rotors 65 are fixed to their respective axle sections by keys 75, or their equivalents,

and the turning axes of the rotors 65 are eccentric to the axes of the chambers 66, which chambers are accordingly of larger diameter inside than the diameter of the rotors. The rotors 65 contact at one side with the inner faces of the chambers 66 and at other points are spaced from said faces. The rotors 65 are provided with radial slots 76 in which are m'ovablv mounted vanes 77 which are urged outwardly by coil springs` 78, beneath them, into engagement with the inner face of the housing 67.

At one side, the housing 67 is provided with a valve chamber 79 in which is mounted a rotary valve 80, and leading from opposite Each camV oints of the valve chamber 79 are ports 81,

2 that branch and communicate with both chambers 66. The ports 81, 82 communicate with each of the chambers 66 at spaced points that are less than 90 but more than 45, apart. Each of the chambers 66 is, inits inner face, provided with a by-pass channel 83 that, in Figure 12, extends from the port 81 counterclockwise to a point adjacent to where the rotor contacts with the chamber wall. Each of the chambers 66 is, also, provided in its inner face with another by-pass channel 84 that extends from the port 82 clockwise adjacent to the point where the rotor contacts with the chamber wall. The channel 83 prevents back pressure against the vanes 77 whenthe rotors 65 rotate counterclockwise, and the channels 84 accomplish the same thing when said rotors turn clockwise, for it is intended that the rotors operate in either direction according to the position of the valve 80.

Longitudinally in its periphery, the valve 80 is provided, at different circumferential points, with ports 85, 86, 87 and 88, the ports 85, .86 opening to one end of the valve 80 so as to communicate with the space 89 of the valve chamber 79 adjacent to said end, and the ports 87, 88 opening to the other end of said valve so as to communicatev with the space 90 of said valve chamber adjacent to said other end.

The pi e 16 communicates with the space 89 and t e pipe 17 communicates with the space 90. The stem 91 of ,the valve 8O projects through a stuiiing box 92, in one end of the valve chamber 79, to the outside of said valve chamber and the projecting end is provided with an arm 93 to which is connected one end of the operating rod 94, the other end of said rod extending to within convenient reach of the operator.

Assuming that the prime mover C is operated at an idling speed and that all of the valves 33 are in the same position as that valve illustrated in Figure 4, that the valve 18 is closed, and that the valve 80 is in the osition illustrated in Fi res 12 and 13,V the invention operates as fol ows:

The operator opens the valve 18 `and he then operates the rod 50 to move the torwardmost valve 33 of the series into a position corresponding to that in which one of the valves 33 is illustrated in Figure 5, thereby causing the oil pumped by thel rotor, associated with the hand-operated valve, to pass through the associated port 31 and throughv the valve chamber 32 and port 36 into the pipe 16, thence to the space 89, thence through the port 85 into the port 81, thence into the chambers 66 so as to propel the rotors 65.clockwise in Figure 12, thereby starting'the wheels D into operation in a direction to move the motor-vehicle forward or to the right in Figure 1. It is up the rotors and, accordingly, causes the` governor to turn the rock shaft 54 clockwise in Figure 4, thus to actuate that rocker arm 38 which is the second one from the forward end, thus actuating the associated valve 33 to the position illustrated for the valve 33 in Figure 5, thereby causing an additional volume of oil to be pumped by the second rotor 19 to the propelllng rotors 65.

As the operator continues to open up the throttle, assuming that the motor vehicle is running on level road without much resistance to its travel, the valves 33 will be actuated in succession into position to discharge the oil from the associated compartment into the pipe 16 and thence to the rotors 65. Oil is exhausted from the chambers 66 through the ports 82, 87 into the space 90, thence through the return line 17 to the reservoir 29.

Assuming, now, that the character of the road is such that the load on the engine increases, thus slowing down the motor vehicle,

as would be the case, for example, if the motor vehicle were driven up a grade, the speed ofV rotation of the governor 49 would decrease, thus turning the rock shaft 54 in Figure 4 in a counterclockwise direction, thereby actuating the rocker arms 38, beginning at the rearmost one, into positions to depress the valves 33, one at a time, into the position illustrated in Figure 4 so as to by-pass the oil pumped from the associated compartments by the rotors therein. The more the speed of the vehicle decreases, the greater the number of valves 33 that are actuated into position to by-pass the oil.

To stop the vehicle, the operator will close the throttle of the prime mover C and then operate the rod 50 into position to cause the associated valve 33 to assume the position indicated for one of the valves 33 in Figure 4 and, as the vehicle slows down, the remaining valves 33 that may be in the position illustrated in -Figure 5 will be automatically.

actuated by the governor into the oil bypassing positions. The operator may .apply the usual brakes or, in lieu of securing the braking action with the usual brakes, the operator may cause a braking action on the vehicle by gradually closin the valve 18 so that a back pressure will e produced of the oil in the return line 17 upon the rotating vanes of the rotors 65.

15. If the operator desires to back the vehicle, the rotors 65 may be driven in a reverse direction and to accomplish this the operator moves the rod 94 in a direction to turn the valve 80 into the position illusf trated in Figure 14. In this position of the valve 80 the oil is pumped through the ports 86, 82 thereby turning the rotors (i5-counterclockwise in Figure 12. The exhaust oil, in this case, Will pass through the ports 81, 88 into the space 90, thence through the return line 17 to the reservoir 29. I

In the foregoing, it will be readily understood that by employing the hereinbefore described mechanism, the gear transmission, the clutch, and the gear differential ordinarily employed in motor vehicles can be eliminated.

In practice, if desired, the relative capacities of the compartments 23 and chambers 66 may be such that the operation of one of the rotors 19 will result in a speed ratio of 1 to 12, of two rotors 1 to 6, of three rotors 1 to 4, of four rotors 1 to 3, of five rotors 5 to 12, of six rotors 1 to 2, of seven rotors v7 to 12, and of eight rotors 2 to 3.

I claim:

A power transmission mechanism comprising, a reservoir, a pumping unit receiving liquid from the reservoir and provided with a series of separate compartments and with pumping elements in said compartments, a means to operate the pumping elements, a propelling unit, a return pipe line connecting the propelling unit withvthe reservoir, a pressure pipe line connected with the propelling unit, a Avalve means for each compartment operable in one position to by-pass liquid from the associated compartment to the reservoir and operable in a second position to pass liquid from the associated compartment t-o the pressure pipe line, 'a manually operated means to operate one of the valve means, a governor operably connected with the propelling unit, and a means operable by the governor to selectively actuate the other valve means.

Signed at Los Angeles, California, this 30th day of Januar 1929.

. YIARRY H. BROWN. 

